Unless the previous owner has upgraded the whole headlight unit to projector/xenon or they are factory fit projectors you've probably got Xenon look halogen bulbs installed? Easiest way to tell would be that the bulbs themselves would be blue or have a blue tinge.
If you're wanting to upgrade the fogs they're either going to be HB4 or H11 bulbs, that's if they're factory fitted.
In my Polo I ran MTEC Super Whites and can fully recommend them based on output and longliviety. The output will never be as good as standard "yellowish" bulbs though unless you go down an aftermarket projector/hid route.
Halogen headlights.
Projector headlights.
If you need further help, post up a photo.
Dom
